For the developing countries taken as a whole, the impli< petuation of current high levels of fertility over the next 20 with prospective declines in mortality, is clear: the school-^ would grow very rapidly, and their share of the total popul; slightly above its current level. With moderate declines in ferl Nations' medium projection indicates that the share of the scl lation (aged 5 to 14) would remain virtually unchanged up t rate of increase during the 1970's, at 2.2 percent per annurr slightly below that of the total population (21, Annexes 2, this projection, the school-age population has already reach rate of growth. The rate is likely to climb higher during th tively few areas, notably parts of Africa and southwest Asia.
If widespread and rapid reductions in fertility should occu impossible), the growth rate of the school-age population wot quickly although numbers at school age would nevertheless r tially during the 1970's and into the 1980's.
If fertility declines at about the rate implied in the Uni1 dium projection, the total number of school-age children \ rapidly.* The growth rate of the school-age population dur cade will be faster than during the past two decades, and ab is at the current time; and two decades from now, the absol the school-going age groups each year will be about two-thin is at present. The financial implications of bringing a higher p: expanding group of "eligibles" into the school system are obv
The Shortage of Teachers
The age structure that will continue to characterize the c tries for at least the next decade is an unfavorable one, not the high dependency rates, but also in terms of potential tea developing country that has been making rapid progress in e places, the cohorts from which potential teachers must b substantially smaller and much more poorly educated. A sim illustrate the point. Figure 3 is based on population data froi country with high fertility and moderate mortality, whose trends are a composite of those in developing countries fo: available.t It is striking that the total number of persons
*A number of demographers believe that the United Nations' medi' to understate the increase in world population between now and the excellent summary of alternative points of view, see the papers by Ma< (24).
TThe birth rate in this hypothetical country was 44.3 per 1,000,rovements in commercial marketing channels will make it easier for them to hold the number of children in the family down to the desired number. Thus trends in fertility and in infant mortality will, in most instances, be operating in opposite directions on the number of potential additions to the school population. At current fertility and mortality levels, the potential impact of lowered fertility in reducing the increments to the school-age population is substantially greater than that of lowered mortality in raising them, because in most cases death rates are already low while fertility remains high. The extent to which this potential will be realized willio of private expenditure to public expenditure on education varies between countries. There is unfortunately a dearth of intercountry comparative information on private expenditures on education.al-urban migration, in the multilingual character of the society, in the existence of polygamy, and